1. Field of the Invention
The present invention relates to an auto changer which can store a number of storage media, such as discs, and play back the discs one at a time.
2. Description of the Related Art
In general, an auto changer 10, as shown in FIG. 94, which stores a plurality of storage media, for example, CDs (compact discs) and plays back the stored discs one at a time, is currently used. In the auto changer 10, a stocker 12 which can move vertically and a player 13 for playing back a disc 1 are positioned in a rectangular solid cabinet 11. The stocker 12 can store some discs 1. The player 13 is comprised of a chucking mechanism for discs 1 and an optical pickup. A tray 14 can slide through a portal 14 of the cabinet 11 in order to remove discs 1 from and load discs 1 into the unit.
FIG. 95 shows the order for disc storage and playback operations for the auto changer 10. In the disc storage and playback operations 20, a determination is made whether or not a disc number is specified (in step 421), and when a disc number is specified, a determination is made whether or not a disc 1 is placed on the tray 14 (in step 422).
When a disc 1 is placed on the tray 14, the disc 1 is transferred to a predetermined position in the stocker 12, which is the original position of the disc 1 before the disc 1 was transferred to the tray 14 (in step 423).
The stocker 12 moves so that the storage position of the specified number corresponds to the level of the tray 14 (in step 424), and the disc 1 of the specified number is transferred to the tray 14 (in step 425). In step 425, when there is no disc 1 in the storage position of the specified number in the stocker 12, the same transfer operation as described above is performed. In step 422, when there is no disc 1 in the tray 14, the stocker 12 moves so that the storage position of the specified number corresponds to the level of the tray 14, and the operation described above is performed.
After the disc 1 is transferred in step 425 or when the disc number is not specified in step 421, a determination is made whether or not a tray open/close button has been turned on (in step 426), and a determination is made whether or not a playback button has been turned on (in step 427). Because the tray open/close button and the playback button can not be simultaneously turned on, two of them are checked. For example, when the tray open/close button has been turned on in step 426, the tray 14 is opened (in step 428). A disc 1 can be placed on the opened tray 14.
A determination is made whether or not the tray open/close button has been turned on (in step 429), and when it has been turned on, the tray 14 is closed (in step 430). The presence or absence of a disc 1 on the tray 14 is determined, the determination is displayed (in step 431), and the disc 1 is clamped (in step 432), at which point the disc storage operation is completed.
When the playback button has been turned on in step 427, a determination is made whether or not there is a disc 1 on the tray 14 (in step 433). When there is a disc 1, the playback operation is performed (in step 434). A determination is made whether or not the playback operation is completed (in step 435). When there is no disc 1 on the tray 14 in step 433, the playback operation is completed.
However, with the auto changer 10 currently in use, the disc 1 on the tray 14 is clamped by the chucking mechanism for the playback operation. During the playback operation for the disc 1, the tray 14 cannot be moved, and it is inconvenient for the user who cannot store a disc 1 into the stocker 12 or take out a disc 1 in the stocker 12 during playback.
Further, when the disc 1 is transferred into the player 13 or the tray 14, a push lever which is positioned at the back of the stocker 12 pushes the disc 1 onto the player 13 or the tray 14. Accordingly, space in which the push lever and the other parts are mounted is required, making the unit large.
Moreover, the disc 1 is merely placed on a disc space which is a hollowed area on the tray 14, and when there is a shock or a vibration, the disc 1 may move out of position. In such situation, when the playback operation is performed, the player 13 may clamp the disc 1 out of the appropriate position, damaging the signal recorded area. The disc 1 may also fall inside the unit due to a great shock or vibration, damaging the unit.
Generally, the auto changer 10 plays two kinds of discs, 12 cm discs and 8 cm discs. The mechanism in the unit, for example, the disc area on the tray 14 is designed for the 12 cm disc. Accordingly, when the 8 cm disc is placed on the tray 14, it may easily move out of position and fall inside the unit.
Generally, the auto changer has a sensor which detects the size and the presence or absence of the disc 1. However, when a user accidentally place two discs 1 on the tray 14, the sensor cannot detect both discs 1 and the tray 14 is closed so that the discs 1 are transferred to the stocker 12. Because a compartment in the stocker 12 corresponds to the thickness of one disc 1, one of two discs 1 is not transferred into the stocker 12, remaining at an inappropriate position or falling inside the unit. In this situation, when the stocker 12 is moved or the playback operation is performed, the disc 1 or the unit may be damaged.
Further, when the user accidentally places an 8 cm disc 1b on a tray 14 for a 12 cm disc 1a, the sensor may detect the disc 1 which is being transferred into the unit. However, because the mechanism in the unit, for example, the disc space which is a hollowed area on the tray 14 is designed for a 12 cm disc 1a, the storage operation and the playback operation cannot be correctly performed. In such situation, the disc 1b may move out of position or fall inside the unit, and the problem described above arises.
Moreover, when the power supply to the unit is stopped during operation, the auto changer 10 cannot later recognize the positions of the disc 1, the tray 14, and the stocker 12. When a disc 1 is positioned between the tray 14 and the stocker 12 and the power is supplied again, the stocker 12 moving up or down, may collide with the disc 1 positioned between the tray 14 and the stocker 12, so that the disc 1 may be damaged or fall inside the mechanism, or the unit may damaged.
Moreover, when the data for the storage status is lost due to an electricity failure, a disc 1 on the player 13 may be transferred to a compartment in the stocker 12 where another disc 1 is already stored, during the next operation. In this situation, the disc 1 which was set on the player 13 pushes the other disc 1 stored in the stocker 12, and both of the two discs 1 may be damaged.
Moreover, when a disc 1 in the stocker 12 is played back, the stocker 12 moves up or down in order to transfer the selected disc 1 to the level of the player 13, and the disc 1 is transferred to the player 13 by an appropriate transfer means. When the disc 1 is played back or when the unit is turned off, the stocker 12 remains at that position.
However, when the stocker 12 remains in such position and there is a shock or a vibration, the stocker 12 may fall, and the stocker 12 or the discs 1 stored in the stocker 12 may be damaged.
Moreover, when there is a shock or a vibration, the disc 1 may move out of the player 13 or fall from the stocker 12 onto the player 13, and the unit may be damaged due to such disc 1.